Exam 1 Review Flashcards
6 functions of bone
- Mechanical Support
- Protection
- Facilitates Movement
- Mineral Storage
- Blood Cell Production
- Energy Storage
Cellular Composition of Bone
-30% Organic
-70% Inorganic
Primary Bone Cells
Osteoblast
Osteoclast
Example of inorganic bone compound
Hydroxyapatite
Example of organic bone compound
Collagen
Osteoblast
Bone formation
Osteoclast
Bone reabsorption
Define bone remodeling
Involves the removal of mineralized bone by osteoclasts followed by the formation of bone matrix and mineralization through the activity of osteoblasts.
Phases of bone remodeling
Reabsorption
Reversal
Formation
Reabsorption phase of bone remodeling
Osteoclasts digest old bone
Reversal phase of bone remodeling
mononuclear cells appear on bone surface
Formation phase of bone remodeling
Osteoblasts lay down new bone until the reabsorbed bone is completely replaced.
Wolff’s Law
- Natural healthy bones will adapt and change to adapt to the stress that it subjected to
- “Bone will be laid down where needed
and resorbed where not needed.”
Piezoelectric Effect
Ability of certain materials to generate an electric charge in response to applied mechanical stress
Phases of Piezoelectric facilitated bone remodeling
- Mechanical load causes slippage of collagen fibers
- Fiber slippage results in a movement of ions across the bone surface
- Ion movement produces an electrical potential across the bone
- Shift in electrical potential attracts osteoblasts
- Osteoblasts begin to deposit minerals (primarily calcium)
- Formation of new bone tissue
What is the primary takeaway of the Piezoelectric effect in terms of bone remodeling?
External forces induce an electrical charge which may lead to bone healing and repair
How is bone stress influenced by muscle activity?
Muscles create movement by exerting their forces on bone, this can create tensile and compressive forces in the bones with which they interact.
Example of bone compressive forces
Ski boot
- Tricep surae (gastroc and soleus) exert compressive forces on the posterior aspect of the shank, neutralizing the high tensile forces applied to it.